1. Field of the Invention
This invention relates to a device and to method. More specifically, this invention relates to a medical device, in the form an improved syringe for dispensing or, alternatively, collecting of potentially infectious biological fluids; and, to the method for the isolating such fluids within the collection device.
2. Description of the Prior Art
The prior art is replete with various contrivances for use in combination with a syringe/needle to both protect and isolate the needle, both before and after use, so as to prevent inadvertent injury to a clinician or phlebotomist. In addition, the illicit and multiple use of a syringe/needle has also been the subject of intense focus because of the prospect of transfer of infectious diseases. In each instance, the expedient suggested has been, with minor variation, essentially the same. The needle is initially isolated from the ambient environment prior to use, and subsequent to use, the needle and/or the barrel of the syringe rendered inoperative (preferably without exposure to the collected fluid or to the injury from the used needle). The following patents are representative of the relevant prior art and, are therefore discussed herein. The following patents are discussed in chronological order of their date of issue and, thus, no significance is to be attached to the order of their discussion.
U.S. Pat. No. 2,704,073 (to Jensen, issued Sep. 21, 1953) describes a unique solution dispensing device in the nature of an ampoule or vial having a conventional end (e.g. septum closure for access of medicant fluid contents) and a reciprocating syringe-like piston assembly fitted into the based of the solution container. This piston is connected to an internally mounted needle which is contained within the vial/ampoule. Upon exertion of pressure on the plunger, the needle is advanced a short distance within the vial until it penetrates the septum (from within the vial). It is then available for placement at the dispensing/administration site. Upon insertion of the needle into the patient, the plunger is then advanced further. The further advancement of the plunger, allows for the contents of the vial to be drawn/forced through a hole in the needle shaft and thereby delivered/dispensed fluid from the exposed end thereof. The continued advancement of the plunger within the vial forces the contents from the vial and through the needle. The obvious disadvantage of this system is that the needle also continues to move relative to and in response to the pressure on the plunger, and thus may inadvertently extend beyond the desired depth of tissue penetration or possibly puncture a blood vessel. Moreover, the design adopted by patentee is apparently only useful in the dispensing of the contents of the vial, as opposed to sample collection, because the position of needle changes in the course of movement of the plunger/ram, as does the accessibility of the fluid channel through the needle into the container.
U.S. Pat. No. 5,002,533 (to Jullienxe2x80x94issued Mar. 26, 1991)xe2x80x94describes a needle guard for use with a hypodermic syringe. The needle guard comprises a retractable tubular member that fits over the syringe barrel. The end of the guard is provided with an end-piece that permits, alternate, opening and closing of an aperture at the end of the guard so as to allow the syringe needle to pass through the aperture in the end of the guard upon the retraction of the guard over the syringe barrel. In one of the embodiments of the Jullien device, the end piece is repositioned over the aperture at the end of the guard upon the extension thereof over the needle. The needle is once again forced forward and into the end-piece and thereby blunted, bent or otherwise rendered inoperative so as to prevent its re-use.
U.S. Pat. No. 5,057,087 (to Harmonxe2x80x94issued Oct. 15, 1991) describes a hypodermic needle safety system in which the exposed needle is protected by a removable protective cap. The removable cap is held in place by friction fitting thereof to the end of an axially movable safety sleeve. In use, the cap is removed and the safety sleeve retracted and locked in place on the syringe barrel. Upon conclusion of use of the syringe, the safety sleeve is extended to once again surround the needle. The extent of extension of the safety sleeve is somewhat more advanced than its initial position prior to use to allow for the coupling/locking engagement thereof to the end of the syringe barrel upon its reinstallation. More specifically, the additional extension/advancement of the safety sleeve causes one or more dxc3xa9tentes within the protective sleeve to engage and lock the movable safety sleeve onto the syringe barrel upon its insertion of the sleeve. Thus, the syringe can no longer be re-used, while once again protecting one from exposure to injury and transmission of disease.
In one of the alternative embodiments of the Harnon device a sealant/adhesive is disposed at the interface of the guard and the syringe barrel to effect sealing of the guard to prevent inadvertent discharge of fluids from the syringe.
U.S. Pat. No. 5,125,908 (to Cohenxe2x80x94issued Jun. 30, 1992)xe2x80x94describes a hypodermic syringe with a protective holder. The protective holder comprises a tubular structure fitted to the barrel of a syringe. The syringe operates by dispensing fluids from a needle that extends through an aperture in the end of the protective holder. A rubber plug is fitted onto the end of the needle to protect it from damage during the assembly of the syringe and protective holder. Prior to use, the protective holder is retracted to permit advancement of the needle through the aperture at the end of the holder. In the course of advancement of the needle, the needle penetrates the rubber plug that is displaced relative to the needle tip. The contents of the syringe are then dispensed in the traditional manner. Upon completion of the use thereof, the protective holder is re-positioned over the needle from its retracted position to it original protective position; and, the aperture at the end thereof capped as before. Upon retraction of the needle, the rubber plug is not re-positioned over the end of the needle but rather remains remote from the tip of the needle and the aperture in the end of the protective holder.
U.S. Pat. No. 5,139,490 (to Vetter et alxe2x80x94issued Aug. 18, 1992) describes a hypodermic syringe that is typically pre-filled with a medicinal solution (e.g. insulin). The syringe barrel is capped on the dispensing end thereof with a rubber/elastomer seal; and, is fitted on the opposite end of the syringe barrel with a plunger. Prior to use, a needle is fitted to the dispensing end of the barrel. The needle is double ended and, upon mounting to the syringe, pieces the rubber/elastomer seal with one (the distal) end thereof. The act of mounting of the needle on the syringe barrel, thus, causes the distal end of the needle to puncture the seal on the dispensing end of the syringe barrel and thereby permits the plunger to dispense the contents of the syringe through the needle. Presumably the needle can then be removed and the fluid contents remaining within the syringe resealed for use at a later time. Vetter does not disclose how he disposes of the used needle, and presumably it is not reused but rather discarded in the conventional manner.
U.S. Pat. No. 5,647,849 (to Kalin issued Jul. 15, 1997) describes a self-contained safety syringe similar in concept to the device discussed herein relative to U.S. Pat. No. 5,057,087 (to Harmon). The Kalin device is provided with a safety shield that is slidably mounted on a syringe barrel. The open end of this safety shield is covered with a removable cap (and presumably discarded). When it is time to use the syringe, the cap is pealed off the end of the safety shield and the safety shield retracted over the barrel. In one of the alternative embodiments of this invention, the cap is not separately removed, rather the needle simple punctures this shield upon relative movement of the shield and the needle, as the shield is retracted over the barrel, Summary of the Invention, Col. 3, lines 22-26. There is no drawing specifically illustrating this alternative and it is assumed that the FIGS. (and their respective descriptions) that are included are inclusive of this alternative. 
Each of the opposing surfaces of the safety shield and the syringe barrel are provided with a series of detentes for releasable engaging the shield relative to the barrel. Thus, once the syringe has been used, the shield is disengaged from its retracted position on the syringe barrel and once again extended so as to re-position it over the exposed needle.
As is evident from the foregoing the abbreviated review and discussion of the prior art, a number of inventions have endeavored to provide a shield or guard to protect syringe users from injury and disease, by physical isolation of a hypodermic needle within a retractable (e.g. reciprocating) or removable shield. In each instance, the shield or guard is configured to provide a physical barrier to prevent inadvertent contact (and possible puncture) with the needle. Notwithstanding such features, none of the known devices provide effective protection from unintended exposure to the contents of the syringe in the event of leakage or inadvertent discharge of the contents of syringe from the needle. A possible exception to the above, is the device described by Harmon (U.S. Pat. No. 5,007,087) where redeployment of the Harmon shield causes dispensing of an adhesive at the interface of the guard and the syringe barrel and thereby glue the two components to one another. This latter configuration, however, is still not generally leak-proof. Thus, there continues to exist deficiencies in the prior art devices as to the provision of a fluid collection syringe configuration that can prevent inadvertent discharge/spilling of fluid from the syringe (the latter being of significance where the contents of the syringe contain an infectious sample or a solution containing a radioactive isotope.
It is the object of this invention to remedy the above as well as related deficiencies in the prior art.
More specifically, it is the principle object of this invention to provide a medical device that is both safe and effective for the collection and/or dispensing of fluids, and the containment of such fluid within the device, so as to prevent inadvertent discharge.
It is another object of this invention to provide a disposable (single use) syringe/needle combination having an axially movable, reciprocating guard to protect the needle prior to use, retracts during use and, thereafter, upon redeployment, seals the needle within a fluid tight environment.
It is yet another object of this invention to provide a disposable (single use) syringe/needle combination having an axially movable, reciprocating guard to protect the needle prior to use, retracts during use and, thereafter, upon redeployment, concurrently renders the syringe inoperative, and minimize inadvertent discharge of fluid.
Additional objects of his invention include the provision of a method for the protection of an individual from injury and/or infection by the effective sealing of a needle and the fluid contents of a syringe with a leak-proof guard disposed on the dispensing/collection end of the syringe.
The above and related objects are achieved by providing a single use, disposable syringe/needle combination wherein an axially movable, reciprocating shield or guard is slideably mounted over the barrel on the dispensing/collection end of the syringe to protect and shield the needle from contamination prior to use, retracts to permit accessibility of the needle for dispensing and/or collection of fluid through the needle, and, thereafter, subsequent to use, redeployment of the guard, to effectively isolates and seals the needle in a fluid tight chamber, so as to prevent any residual fluid or tissue that may be present thereon, from contact with a health care professional or the environment of the health care professional. This axially movable, reciprocating guard is preferably tubular, of a regular or essentially uniform inside diameter, and has an open, or distal end, and a closed, or proximal end. The inside diameter of the guard is of essentially the same dimension as the outside diameter of the syringe barrel and slidingly mounted on the barrel, at the distal end thereof, by means of one of more features/elements which are complimentary to features/elements on the barrel. This distal end of the guard is further provided with means for engagement of the barrel, on at least three (3) distinct positions, depending the life/use cycle of the device:
at time of shipmentxe2x80x94to protect the needle from contamination in shipment and prior to use,
at time of collection or dispensing of fluid through needlexe2x80x94in a retracted position to permit accessibility of the needle for collection or dispensing fluid relative to the syringe barrel and,
at time of disposalxe2x80x94subsequent to use and upon re-deployment, to seal the needle in a fluid tight compartment.
It is emphasized that the relative position of the guard on the syringe barrel is, in each instance, determined by the placement of a complimentary and engaging feature which is preferably molded into the outer surface of the syringe barrel.
In one of the alternative embodiments of this invention, the redeployment of the guard extends the proximal end thereof beyond its original (shipment) position relative to the syringe barrel so as to engage an element on the barrel and thereby cause such element to penetrate through the barrel and thereby render the syringe permanently inoperative. In a preferred embodiment of this alternative configuration, this element (which can be attached to either the guard or the syringe barrel) is movable or hinged so that upon extension of the guard to its outermost position (and the relative movement of such locking element vis-a-vis the syringe barrel), the guard exerts pressure on such element and causes such element to pierce the syringe barrel, thereby rendering it useless. It is important to emphasize that notwithstanding the damage caused to the syringe barrel, any residual fluids that may remain within the syringe are confined within the leak proof guard.
As is evident from the following description and accompanying Figures, the overall length of the guard is somewhat longer that the needle and terminated on the proximal end thereof with a self-sealing, preferably elastomeric, membrane or septum, such as that typically used on a vial or other container commonly used to store sterile solutions. The location/position of the self-sealing membrane or septum is coincident with the projected path of the needle through the proximal end of the guard. Upon axially movement of the guard, the needle is urged forward and through this self-sealing membrane or septum. Upon emergence of the needle from the sealed environment of the guard, through the self-sealing membrane or septum, the syringe can be used in the conventional manner to collect a biological fluid sample, or dispense a fluid (e.g. insulin solution) contained therein.
Upon retraction of the guard, it is unobtrusively secured in place, on the syringe barrel by means of one or more surface or detente features that releasably engage the interior surface of the guard and with a complimentary feature on the surface of the syringe barrel. The engagement of the guard and syringe barrel can be effected by simply making the syringe barrel irregular or of a larger diameter at the proximal end thereof.
Upon completion of the sample collection, or alternatively, the medicant dispensing cycle, the needle is withdrawn from the patient, and the syringe contents are secured. This is achieved by a combination of processes which can include the physical separation of, for example, a Vacutainer-like vessel from the syringe barrel, or alternatively, the dispensing of an aliquot of the sample into a separate container/sample tubes for further analysis/storage, or alternatively, the dispensing of an aliquot of the sample into the fluid tight guard and thereafter separation of the guard and needle from the syringe barrel.
The re-deployment of the guard secures the needle within a sealed and protected environment. As above noted, such redeployment of the guard subsequent to use, can also concurrently render the syringe barrel and/or plunger inoperative by forcing a piercing element through the wall of the syringe barrel incident to locking the guard in place for safe disposal of the syringe.